The present invention relates to hybrid drive apparatuses.
Japanese Patent Application Publication No. JP-A-2005-206136 (FIG. 17), for example, discloses a structure shown in FIG. 42 in which a hybrid drive apparatus has a state in which it functions as an electric torque converter. This hybrid drive apparatus is provided with an input shaft I that is connected to an engine, an output shaft O that is connected to wheels, a first rotary electric machine M1, a second rotary electric machine M2, a power distribution mechanism SP that includes a double pinion planetary gear apparatus PG, and an automatic transmission AT that is serially connected via the transfer member T between the power distribution mechanism SP and the output shaft O. Here, as rotating elements, the planetary gear apparatus PG is provided with a sun gear ss, carrier cas that supports a plurality of pinion gears that mesh together, and a ring gear rs that meshes with the sun gear ss via the pinion gears. In addition, the carrier cas is connected to the input shaft I and the engine (not illustrated), the sun gear ss is connected to the first rotary electric machine M1, and the ring gear rs is connected to the transfer member T and the second rotary electric machine M2. In addition, a switching brake B0 is provided between the sun gear ss and the transmission case Ds, and a switching clutch C0 is provided between the sun gear ss and the carrier cas. When the switching clutch C0 and the switching brake B0 are released, the planetary gear apparatus PG functions as a continuously variable transmission having a gear change ratio that changes continuously.
Here, because the planetary gear apparatus PG is of a double pinion type, the order of the rotational speeds is: the carrier cas, the ring gear rs, and the sun gear ss. Therefore, when the first rotary electric machine M1 that is connected to the sun gear ss functions as a reaction force point on the rotational torque of the input shaft I (engine), the rotation of the input shaft I (engine) that is connected to the carrier cas is reduced and transferred to the ring gear rs. In addition, the rotation of this ring gear rs is transferred to the automatic transmission AT side via the transfer member T, and it is output from the output shaft O. Here, where λ denotes the gear ratio of the planetary gear apparatus PG (the ratio of the number of teeth of the sun gear ss and the ring gear rs=[number of teeth on the sun gear ss]/[number of teeth on the ring gear rs]), the relationship engine torque: output torque of the planetary gear apparatus: torque of the first rotary electric machine=(1−λ):1:λ is established. Therefore, for example, when the gear ratio λ=0.5 approximately, a torque that is approximately twice the engine torque is output from the carrier cas because the first rotary electric machine M1 distributes a torque that is equivalent to the engine torque. In addition, it is possible to start the vehicle smoothly by using the output torque that is approximately 1/(1−λ) times the engine torque because the reaction force is increased by gradually increasing the torque of the first rotary electric machine M1. Thereby, this planetary gear apparatus PG functions as an electric torque converter that starts a vehicle while multiplying and outputs a rotational torque of the engine by using the torque of the first rotary electric machine M1.